Sealing bellows for ball joints

ABSTRACT

A sealing bellows for a ball joint having its ball stud normally eccentrically located with regard to the ball joint housing, in which said bellows is asymmetric with an unilaterally enlarged bulge.

n 1 1 mnnmn 1721 lnventor Rudo|1Gottschald.deceased (56]lkeferencwsCited late of Osterath Germany (by Erika UMTED STATES PATENTSGottschald me Schlenstedt heir 01 Am 3,208,290 9/1965 Mathues et al.287/90 A X Appl M 3x22? Germany 3,355,199 11/1967 Melton et a1 287/90 A1221 Filed May 2111, 19m FOREGN PATENTS [45] Patented Aug.3, 19711,093,683 11/1960 Germany 287/90C [32] Priority 1V1ay23,1%7 954,6904/1964 Great Britain 287/90 A [331 Germany Primary Examiner-Robert 1.Smith [31 i P 16 00 Auorney-Walter Becker 1541 SEAMNG MElLlLUWS FORllBAlLlL .BOHNTS 2 Clln'nms, ll Drawing lFigs.

lFlB. 287/90 R [51] llnt. Cl 1 lFllfij 3/00 AhS'llltAC'll: A sealingbellows for a ball joint having its ball [50] Field ofSem-clh 277/212.stud normally eccentrically located with regard to the ball 2 2 2 2 F.212 PB; 237/37, 90 1 1 joint housing, in which said bellows isasymmetric with an uni- C laterally enlarged bulge.

ifatented Aug. 3 1971 INVENTOR.

SEALING BElLlLOWS FOR BALL JOINTS The present invention concerns asealing bellows for sealing the housing opening of a ball joint with aball stud which in its normal position is eccentrically located. Thepresent invention is particularly directed to ball joints for motorvehicles. Sealing bellows of the above-mentioned type are necessary notonly for protecting the ball joint against the entry of soil and waterbut also to prevent the escape oflubricant.

The-heretofore-known sealing bellows for ball joints are provided with asmaller opening for the passage of the ball stud and with a largeropening for connecting the bellows to the housing.

It is an object of this invention to provide a sealing bellows whichwill permit a reliable sealing ofa ball joint while the ball stud, whenoccupying its normal position, is eccentrically arranged and is tiltedfrom said eccentric position during the actuation of the joint.

It is another object of this invention to provide a ball joint with abellows as set forth above which is simple in construction and reliablein operation.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing, in which:

FIG. I is a vertical section through a ball joint ofa customary designwith a sealing bellows according to the invention, said bellowsoccupying a position corresponding to the normal position of the balljoint.

FIG. 2 is a perspective top view of the ball joint according to FIG. Iwithout sealing bellows.

FIG. 3 represents a side view of the ball joint according to FIG. I withthe ball stud occupying a central position.

FIG. 4 shows the sealing bellows according to the invention prior to itsassembly.

The present invention has realized the aboveoutlined objects bydesigning the bellows asymmetric with a unilateral bulge. In conformitywith the present invention, the surfaces of the small and the largeopening of the bellows are directed at an acute angle with regard toeach other, said acute angle corresponding to the angle between thecenterline of the ball joint and the centerline of the ball stud in itseccentric normal position.

In order to be sure that the bellows, when being assembled, will beplaced in proper position upon the housing and will be held in thisposition during operation, the bellows may be provided with markings orthe like which either indicate the position on the housing or bringabout a positive engagement therewith.

Referring now to the drawing in detail, the ball joint comprises ahousing I having arranged therein two bearing cups 2 and 3 which receivea ball head 4 having connected thereto a ball stud 4a. Ball stud 4aprotrudes through one housing opening which latter may be designed as anoblong opening 7. An assembly opening 7a opposite to the mountingopening 7 is closed by a cover 5. A spring 6 rests against the cover andpresses the lower bearing cup 3 against the ball head 4.

The normal position of the ball stud in is shown in FIG. I. The ballstud in, when occupying this position, forms an angle with regard to thelongitudinal centerline of the housing 1 as is also evident from theperspective drawing of FIG 2. The sealing bellows 110 provided againstthe entry of soil and water and also for preventing the escape oflubricant, is connected to the tilted into the central osit ion.

In order to obtain t e said bulge 13, the sealing bellows 10 is shown inFIG. 4 in a position in which the opening surface of the small opening12 is, in order to permit the passage of the ball stud 4a, arranged atan acute angle with regard to the opening surface of the large opening11 for connection to the housing 1, said acute angle corresponding tothe angle between the centerline of the ball joint and the centerline ofthe ball stud 40 when occupying its eccentric normal position.

In this way a shape is obtained which will assure a good seal of theinterior of the ball joint without disadvantageous reaction upon themovability of the ball stud 4a. Due to the fact that in the eccentricnormal position of the ball stud 4a the sealing bellows I0 is notsubjected to any pulling or pushing forces, the lifespan of the bellowsis increased. In order to be sure that the sealing bellows, when beingassembled, will be placed upon the housing 1 in proper position andfurthermore to assure that the bellows will be held in this positionduring the operation of the ball joint, the bellows may be provided withmarkings or the like which in the last-mentioned instance, in additionto indicating the correct assembly, will also prevent the sealingbellows 10 from slipping.

As will be seen from the above, the sealing bellows according to theinvention for ball joints has the advantage that in the eccentric normalposition of the ball stud no forces are exerted upon the bellows andthereby no reaction forces are exerted upon the ball stud. This in turnresults in a longer lifespan ofthe sealing bellows.

It is, of course, to be understood that the present invention is by nomeans, limited to the particular design shown in the drawing but alsocomprises any modifications within the scope of the appended claims.

What is claimed is:

I. A sealing bellows for a ball joint in which the ball is received in asocket in a housing with the axis of the ball stud normally at an acuteangle to the axis of the housing, said sealing bellows having a largeopening on one end to encircle the housing for sealing of that end, asmaller opening on the opposite end to encircle the ball stud forsealing at that end, the plane of said second opening being normally atan acute angle to the plane of said larger opening, said bellowsintermediate its ends extending radially outwardly from the axis of saidsocket on the side of said acute angle a greater distance than on itsopposite side to form a radial asymmetric bulge on the side of saidacute angle, so that as said ball stud moves toward a position coaxialwith said socket, the circumferential wall portion of said bellows willbe flexed without substantially stretching the material and withoutexerting force on the sealing ends of the bellows.

2. A sealing bellows combination according to claim 1, in which theasymmetric bellows is provided with marking means to indicate the properassembly position of said asymmetric bellows relative to the housing towhich it is connected.

1. A sealing bellows for a ball joint in which the ball is received in asocket in a housing with the axis of the ball stud normally at an acuteangle to the axis of the housing, said sealing bellows having a largeopening on one end to encircle the housing for sealing of that end, asmaller opening on the opposite end to encircle the ball stud forsealing at that end, the plane of said second opening being normally atan acute angle to the plane of said larger opening, said bellowsintermediate its ends extending radially outwardly from the axis of saidsocket on the side of said acute angle a greater distance than on itsopposite side to form a radial asymmetric bulge on the side of saidacute angle, so that as said ball stud moves toward a position coaxialwith said socket, the circumferential wall portion of said bellows willbe flexed without substantially stretching the material and withoutexerting force on the sealing ends of the bellows.
 2. A sealing bellowscombination according to claim 1, in which the asymmetric bellows isprovided with marking means to indicate the proper assembly position ofsaid asymmetric bellows relative to the housing to which it isconnected.